docs:
https://github.com/mhulden/foma/blob/master/foma/docs/simpleintro.md
https://fomafst.github.io/morphtut.html
https://fomafst.github.io/regexreference.html

https://code.google.com/archive/p/foma/wikis/FAQ.wiki
https://code.google.com/archive/p/foma/wikis/InterfaceReference.wiki
https://code.google.com/archive/p/foma/wikis/APIReference.wiki
https://code.google.com/archive/p/foma/wikis/APIExamples.wiki
https://code.google.com/archive/p/foma/wikis/RegularExpressionReference.wiki

wiki:
https://en.wikipedia.org/wiki/Foma_(software)
http://wiki.apertium.org/wiki/Foma

http://www.aclweb.org/anthology/E/E09/E09-2008.pdf
http://www.ling.helsinki.fi/kieliteknologia/tutkimus/hfst/
http://clt.gu.se/sites/clt.gu.se/files/mkp/clttutorial.pdf

tutorial:
http://foma.sourceforge.net/dokuwiki/doku.php?id=wiki:morphtutorial